The present invention relates to a route guide data creation method and a route guide data creation device for creating route guide data for a vehicle that travels on a road according to a predetermined travel route and a predetermined travel time, such as a timetable for a route bus, and a route guide distribution device for providing a route guide using the route guide data created by the route guide data creation device. More particularly, it relates to a route guide data creation method and a route guide creation device for creating route guide data by acquiring actual travel data of a vehicle, and a route guide distribution device that distributes a route guide based on the route guide data created by the route guide data creation device.
When visiting a place, which is a destination, in an unfamiliar area, people have been using a map as an aid to reach the destination while confirming roads, landmarks, and addresses on the map. Alternatively, in a vehicle with a car navigation system (hereinafter referred to as a car-navigation), people start said car-navigation, input a destination, and can thereby reach their destination while acquiring guidance displayed on a monitor screen or audio output guidance (navigation information) outputted from the navigation system.
The operating principle behind the above-described car-navigation uses GPS. GPS signals transmitted from a plurality of GPS satellites that travel around the earth are received by a GPS antenna, and positions are specified by analyzing satellite positions, information on distances between the satellites and a receiver, and clock information included in said GPS signals. At least four or more GPS satellites are required for said plurality of GPS satellites. Although single position-fix accuracy is generally a little over 10 m, it can be improved to 5 m or lower by using DGPS (Differential GPS).
In recent years, the performance of mobile communication terminal devices, including mobile phones and PHS, has significantly improved, and multifunctionalization has been in progress. Especially, data communication functions other than call functions have been enhanced, and various kinds of data communication services via the Internet are provided to users. A navigation service is one of them, and experiments for providing a route guide from a current position to a destination not only to drivers of automobiles but also to mobile phone users have been started.
For example, the applicant has disclosed a navigation system using a mobile phone as a terminal in the following patent document 1 (Japanese published unexamined application No. 2003-214860). As shown in FIG. 8, this navigation system includes a mobile terminal (mobile phone) 1 that is to be connected to a traveling body communication network 2 and a data communication service center (information distribution computer system) 3. The mobile terminal 1 receives desired data communication services through connection with the data communication service center 3. If the mobile terminal 1 is a mobile phone or a PHS, a call to desired other end (land-line phone, mobile phone, PHS, etc.) can be made through traveling body communication base stations and telephone line networks via the traveling body communication network 2. The data communication service center 3 is configured as follows for providing route navigation services upon request from the mobile terminal 1.
More specifically, when a route search request including information on a departure point and a destination point is issued from the mobile terminal 1, the information distribution computer system in the data communication service center 3 searches an optimal route from the departure point to the destination point using road data stored in storing means, and temporarily stores searched route data in the storing means as guide route data. When display map information in which position coordinate and a guide route are specified is requested by the mobile terminal 1, the information distribution computer system in the data communication service center 3 reads vector-style map data for displaying a map around the specified position coordinate and the specified guide route data from the storing means. Then, the information distribution computer system converts the guide route data into vector data for displaying roads in a specified color, incorporates the vector data into the map data, and sends the map data to the mobile terminal 1, which is a requestor.
Although it is not shown in figures, the mobile terminal 1 has a GPS receiver for measuring a current position as it changes according to movement, and GPS positioning is performed at predetermined intervals. The mobile terminal 1 issues a request for display map information to the information distribution computer system in the data communication service center 3 when shortage occurs in result display map information of the GPS positioning. Moreover, the information distribution computer system in the data communication service center 3 has a storing means in which road data (map data) and data including landmarks, such as buildings in various places on maps, names of intersections, and names of roads are stored. Maintenance is preformed on the data by acquiring the latest data through information distribution computer systems 5, 6 that distribute maps via the Internet network 4.
Incidentally, in the above-described navigation system, when a route guide is provided for a vehicle that travels on a road based on a predetermined travel route and a travel time, such as a route bus, a timetable does not exist unlike trains or electric trains. As a result, route guide data (timetable data), which is the basis for a route guide, cannot be acquired. For example, the departure schedule (operation schedule) shown in FIG. 9 is posted at a bus stop of a route bus. The departure schedule that shows the departure time at each bus stop may be a timetable in the general meaning; however, it cannot be used as route guide data because data on links between the time at which a vehicle (bus) departs from a bus stop and the time at which the bus departs from the next bus stop does not exist.
Even if a thing such as a train timetable exists, a vehicle that travels on a road, such as a route bus, may not travel between bus stops as scheduled due to traffic conditions (traffic jams) or weather conditions (rain). Namely, the schedule posted at each bus stop is only a rough guide and a timetable created based on the posted schedule is very different from the actual travel time. Thus, the timetable cannot be used as route guide data.
To resolve such inconvenience, efforts are under way to improve users' convenience by collecting data that shows the operation conditions of an actually operating vehicle (information on at what time and from which bus stop a vehicle has departed, information on the current position of each vehicle, and so on) using means such as a radio device, displaying an estimated arrival time at the next bus stop, displaying at what section the operating vehicle is currently located on a route map at each bus stop, or distributing such information to a mobile phone or a CATV receiver.
For example, a bus approaching information display method and device are disclosed in the following patent document 2 (Japanese published unexamined application No. 11-185197). In the bus approaching information display method and device disclosed in patent document 2, bus position information is collected at a bus location center station via a radio transmitter equipped in a bus. The information is transmitted to a bus stop as well as to users' homes via a CATV station. An approaching bus is detected based on the information for each bus route and displayed at the bus stop. Said information is received by a data transceiver provided at each user's home and displayed on a display screen.
Furthermore, a bus stop system is disclosed in the following patent document 3 (Japanese published unexamined application No. 7-320198). Patent document 3 discloses a bus stop system that includes a bus timetable displaying system having a bus stop at which a bus ID, scheduled departure time of a bus stop, scheduled departure time from a previous bus stop are stored in an ID storing section in advance associated with the bus ID, the departed time of the bus from the previous bus stop and the bus ID are received by a receiving section, estimated departure time is calculated by a control section based on the departed time of the bus from the previous bus stop, and a scheduled departure time and a scheduled departure time from the previous bus stop corresponding to said bus ID, and displayed by a display section, and a control method of the bus timetable displaying system.
Various kinds of methods for collecting travel data from a vehicle have been devised or are in practice. For example, there is a method including installing a sensor under a road surface at a bus stop, reading an ID of a bus that has arrived at the bus stop, sending arrived time to a travel management center via radio communication; a method including sending announcements made by a driver to a travel management center via radio communication; and a method sending a current position of each bus by a GPS system installed in the bus.
Patent Document 1: Japanese published unexamined application No. 2003-214860 (FIG. 1)
Patent Document 2: Japanese published unexamined application No. 11-185197 (FIG. 1)
Patent Document 3: Japanese published unexamined application No. 7-320198 (FIG. 5)